Chemical Functionalization of Carbon Nanotubes

Abstract

The invention relates to a process for chemically functionalizing carbon nanotubes. The process comprises dispersing carbon nanotube salts in a solvent; and chemically functionalizing the carbon nanotube salts to provide chemically functionalized carbon nanotubes.

1 . A process for chemically functionalizing carbon nanotubes, the process comprising:
 dispersing carbon nanotube salt in a solvent; and   chemically functionalizing the carbon nanotube salt to provide chemically functionalized carbon nanotubes by reacting oxidizing agents or thermally unstable, radical producing species with the carbon nanotube salt.   
     
     
         2 . The process of  claim 1 , wherein dispersing the carbon nanotube salt in the solvent comprises chemically reducing carbon nanotubes to the carbon nanotube salt, the carbon nanotube salt comprising negatively charged carbon nanotubes. 
     
     
         3 . The process of  claim 2 , wherein chemically reducing the carbon nanotubes to the carbon nanotube salt comprises addition of a radical ion salt of formula A + B −  to the carbon nanotubes in the solvent, wherein A +  is a cation of an alkali metal and B −  is a radical anion of a polyaromatic compound. 
     
     
         4 . The process of  claim 2 , wherein the alkali metal is lithium, potassium, and/or sodium. 
     
     
         5 . The process of  claim 3 , wherein the alkali metal is lithium, potassium, or sodium. 
     
     
         6 . The process of  claim 3 , wherein the polyaromatic compound is naphthalene and/or benzophenone. 
     
     
         7 . The process of  claim 1 , wherein the solvent is a polar organic solvent. 
     
     
         8 . The process of  claim 7 , wherein the polar organic solvent is pyridine, tetrahydrofuran, ethers, 1,2-dimethoxyethane, and/or toluene. 
     
     
         9 . The process of  claim 1 , wherein the chemically functionalized carbon nanotubes comprise functional groups selected from —COOH, —PO 4   − , —SO 3   − , —SO 3 H, —SH, —NH 2 , tertiary amines, quaternary amines, —CHO, —OH, alkyl, alkenyl, alkynyl, cycloalkyl, heterocyclyl, cycloalkenyl, alkoxy, alkanoyl, acyl, aryl, and/or heteroaryl groups. 
     
     
         10 . The process of  claim 9 , wherein the functional groups are alkyl or alkenyl groups. 
     
     
         11 . (canceled) 
     
     
         12 . The process of  claim 1 , wherein chemically functionalizing the carbon nanotube salt comprises reacting oxidizing agents with the carbon nanotube salt. 
     
     
         13 . The process of  claim 1 , wherein chemically functionalizing the carbon nanotube salt comprises reacting a radical producing species with the carbon nanotube salt. 
     
     
         14 . The process of  claim 13 , wherein chemically functionalizing the carbon nanotube salt comprises reacting ozone, dimethylsulfoxide, peroxides, azo compounds, or diazonium compounds with the carbon nanotube salt. 
     
     
         15 . The process of  claim 1 , wherein chemically functionalizing the carbon nanotube salt comprises reacting one or more acyl and/or aroyl peroxides with the carbon nanotube salt. 
     
     
         16 . The process of  claim 1 , wherein chemically functionalizing the carbon nanotube salt comprises reacting R—C(O)O—O(O)C—R′ with the carbon nanotube salt, wherein the R and R′ groups are the same or different and are independently selected from alkyl, alkenyl, alkynyl, alkyl groups containing heteroatoms, alkenyl groups containing heteroatoms, alkynyl groups containing heteroatoms, cycloalkyl, heterocyclyl, cycloalkenyl, aryl, and/or heteroaryl; to provide the chemically functionalized carbon nanotubes, wherein the R and R′ groups are covalently bonded to the carbon nanotubes. 
     
     
         17 . The process of  claim 16 , wherein the R—C(O)O—O(O)C—R′ is selected from benzoyl peroxide, lauroyl peroxide, succinic acid acylperoxide, and/or glutaric acid acylperoxide. 
     
     
         18 . The process of  claim 15 , wherein the R—C(O)O—O(O)C—R′ is selected from acetyl peroxide, n-butyryl peroxide, sec-butyryl peroxide, t-butyryl peroxide, t-pentoyl peroxide, iso-valeryl peroxide, furoyl peroxide, palmitoyl peroxide, decanoyl peroxide, lauroyl peroxide, diisopropyl peroxydicarbonate, butylperoxyisopropyl carbonate, trans-t-butylcyclohexanoyl peroxide, trans-4-cyclohexanecarbonyl peroxide and cyclohexyl peroxydicarbonate, cyclopropanoyl peroxide, cyclobutanoyl peroxide and cyclopentanoyl peroxide, bromobutyryl peroxide, (CCl 3 CO 2 ) 2 , (CF 3 CO 2 ) 2 , (CCl 3 CO 2 ) 2 , (RO(CH 2 ) n CO 2 ) 2 , (RCH═CR′CO 2 ) 2 , RC═CCO 2 ) 2 , (N═C(CH 2 ) n CO 2 ) 2 , where n=1-3, cinnamoyl peroxide, bis(p-methoxybenzoyl)peroxide, p-monomethoxybenzoyl peroxide, bis(o-phenoxybenzoyl)peroxide, acetyl benzoyl peroxide, t-butyl peroxybenzoate, diisopropyl peroxydicarbonate, cyclohexyl peroxydicarbonate, benzoyl phenylacetyl peroxide, butylperoxyisopropyl carbonate, p-nitrobenzoyl peroxide, p-bromobenzoyl, p-chlorobenzoyl peroxide, and bis(2,4-dichlorobenzoyl)peroxide, p-methylbenzoyl peroxide, p-methoxybenzoyl peroxide, o-vinylbenzoyl benzoyl peroxide, and/or exo- and endo-norbornene-5-carbonyl peroxide. 
     
     
         19 . The process of  claim 1 , wherein the degree of functionalization is 1 functional group per 100 nanotube carbons. 
     
     
         20 . The process of  claim 1 , wherein the process is a single-pot process. 
     
     
         21 . The process of  claim 1 , wherein reaction time of functionalizing the carbon nanotube salt is about 30 minutes or less. 
     
     
         22 . The process of  claim 1 , wherein the carbon nanotubes are selected from SWNTs, DWNTs and/or MWNTs. 
     
     
         23 . The process of  claim 1 , wherein the process occurs at a temperature that initiates chemical functionalization. 
     
     
         24 . The process of  claim 1 , wherein the process occurs at about room temperature. 
     
     
         25 . The process of  claim 1 , wherein the carbon nanotube salt is a chemically functionalized carbon nanotube salt. 
     
     
         26 . The process of  claim 1 , wherein the chemically functionalized carbon nanotubes resulting from the process are converted to a chemically functionalized carbon nanotube salt, which is used as the carbon nanotube salt when the process is repeated. 
     
     
         27 . The process of  claim 13 , wherein chemically functionalizing the carbon nanotube salt comprises reacting ozone, dimethylsulfoxide, or peroxides with the carbon nanotube salt.